Technical Field
The present invention generally relates to a liquid crystal display.
Related Art
A liquid crystal display (hereinafter referred to as an LCD) is one of the most widely used flat panel displays. The typical LCD includes two display panels provided with electric field generating electrodes, such as pixel electrodes and a common electrode, and a liquid crystal layer interposed between the two display panels. In the LCD, voltages are applied to the electric field generating electrodes to generate an electric field in the liquid crystal layer. Due to the generated electric field, liquid crystal molecules of the liquid crystal layer are aligned and polarization of incident light is controlled, thereby displaying images. The LCD also includes switching elements connected to the respective pixel electrodes, and a plurality of signal lines such as gate lines and data lines for controlling the switching elements and applying voltages to the pixel electrodes. The liquid crystal display also includes color filters made of an organic material including pigments for realizing colors.
When the pixel electrodes and the color filters are formed on the different display panels, it is difficult to correctly align the pixel electrodes and the color filters, and an alignment error may be generated. To solve this problem, a color filter on array (CoA) structure in which the pixel electrodes and the color filters are formed on the same display panel is provided. In the color filter on array structure, the color filters, the pixel electrodes, a plurality of signal lines for applying the voltage to the pixel electrodes such as gate lines and data lines, and switching elements for driving them are formed on one display panel.
Among the LCDs, a vertical alignment (VA) mode LCD, which aligns liquid crystal (LC) molecules such that the long axes of the LC molecules are perpendicular to the panels in the absence of an electric field, is favored because of its high contrast ratio and wide reference viewing angle. In this case, the reference viewing angle refers to a viewing angle at which a contrast ratio is 1:10 or to a luminance inversion limit angle between grays (e.g., an angle at which gray-scale inversion begins to occur).
In order to cause side visibility to approximate front visibility in the vertical alignment mode LCD, a method of causing a difference in transmittance by dividing one pixel into two subpixels and applying different voltages to the two subpixels has been suggested.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.